﻿#region Copyright and license information
// Copyright 2001-2009 Stephen Colebourne
// Copyright 2009-2010 Jon Skeet
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#endregion

using System;
using System.Linq;
using NUnit.Framework;

namespace NodaTime.Test
{
    public partial class InstantTest
    {

        [Test]
        public void StepBy()
        {
            var duration = Duration.FromHours(2);
            var start = Instant.FromUtc(2001, 1, 1, 0, 0, 0);
            var dates = start.StepBy(duration).Take(3).ToArray();
            Assert.AreEqual(start, dates[0]);
            Assert.AreEqual(start.Plus(duration), dates[1]);
            Assert.AreEqual(start.Plus(duration * 2), dates[2]);
        }

        [Test]
        public void StepBy_Zero()
        {
            var start = Instant.FromUtc(2001, 1, 1, 0, 0, 0);
            Assert.Throws<ArgumentException>(() => start.StepBy(Duration.Zero).ToArray());
        }

        [Test]
        public void StepBy_Overflow()
        {
            var duration = Duration.FromHours(1);
            var start = new Instant(Instant.MaxValue.Ticks - NodaConstants.TicksPerHour * 2);
            Assert.AreEqual(3, start.StepBy(duration).Count());
        }

        [Test]
        public void StepBy_Underflow()
        {
            var duration = Duration.FromHours(-1);
            var start = new Instant(Instant.MinValue.Ticks + NodaConstants.TicksPerHour * 2);
            Assert.AreEqual(3, start.StepBy(duration).Count());
        }
    }
}
